Tips for botulinum toxin injections include using the smallest effective dose, clearly marking injection sites before treatment , and considering male versus female aesthetic standards, an expert says.
National report - To maximize elegant, natural results and patient satisfaction, one expert generally recommends injecting smaller doses of botulinum toxin and repeating treatment if necessary.
This is especially true with male patients, although they require larger total doses than females, says Timothy C. Flynn, M.D., medical director, Cary Skin Center, Cary, N.C.
In recent years, "I've reduced Botox (botulinum toxin A, Allergan) dosing to allow for increased natural expression and movement," he says.
Furthermore, Dr. Flynn says clearly marking injection sites before treatment helps to avoid asymmetry.
Even a small discrepancy in the location of frontalis injections can produce noticeable asymmetry, he says.
"A red dry-erase marker wipes up easily, with no residue. And there's no tattooing," which can occur with some inks, he says.
Additionally, he says when treating the frontalis, particularly in men who have a strong frontalis they're "cranking up" to raise their eyebrows so they can see better, "Consider a sequential, careful treatment. Rather than trying to get every line at once, it may be best to do this slowly."
More specifically, Dr. Flynn recommends preoperatively treating the upper area of the frontalis and seeing what results occur after two weeks.
At that point, the patient may or may not need additional treatments for the lower part of the frontalis, he says.
The fact that men require more botulinum toxin may stem from their having significantly more muscle mass than women, Dr. Flynn says.
In a study that examined overall body musculature, men had an average of 33 kg of muscle versus 21 kg for women (Janssen I, et al. J Appl Physiol. 2000 Jul;89(1):81-88).
"This testosterone effect probably applies also to the facial musculature," Dr. Flynn tells Dermatology Times.
In fact, one study of botulinum toxin dosing for the male glabellar area showed 20 units was inadequate, while 40 to 80 units performed better, providing dose-response and duration effects (Carruthers A, Carruthers J. Dermatol Surg. 2005 Oct;31(10):1297-1303).
"So, when men come in," Dr. Flynn says, "make sure you treat them with enough Botox. You can feel confident there will be no increase in adverse events at the higher doses."
Additionally, he says it's important to consider standards of female versus male beauty.
In comparing software-produced representations of male and female faces, he says, "It's interesting that when one blends these two algorithms together to get a face that's 50 percent female, 50 percent male, the end result is an androgynous-looking face. But such an androgynous face still appears female to most observers."
Therefore, he says that when performing botulinum toxin injections, "Make sure your male patients look male and your female patients look female. If you go halfway between, you might get a result you don't like."
Additionally, he says that although many men respond well to botulinum toxin, it's common for them to require some wrinkle filling, as well, to achieve optimum results.
When treating the female glabella, one should strive for a good effect, Dr. Flynn says.
"The package insert says to use 20 units for the glabella, but most everyone is using a bit more than 20 units in the glabella," he says.
For instance, Dr. Flynn says his usual algorithm involves putting six units in the procerus, then four units in each corrugator - both in the head and the lateral aspect of the corrugator - then about three units in the middle of each corrugator, for a total starting dose of 28 units.
"With this dose, we're getting a very good effect and duration," he says.